Tribological and microstructural evaluation of smooth hot flame deposited diamond films

DEVELOPMENTS OVERPRESSURE

IN VACUUM AND SINTERING

D. Ermel. (ALD Vacuum Technologies GmbH, Germany.) Improvements in furnace design, control systems, furnace temperature uniformity, costs and capacity were reviewed in respect of hardmetal and other PM parts. Processes and applications overpressure

for dewaxing,

sintering

hardening of the binder. A study of the effect of C content on the microstructure

comparison fused WC.

of a complex carbide/nitride cermet with a Co-Ni binder was described. It was shown that the size of the hard particles and

WEAR RESISTANCE OF NONTUNGSTEN CEMENTED CARBIDES

the proportions phases present total XC.

Y. Pirso, P. Kallas. (Tallinn verisity, Tallinn, Estonia)

and compositions were influenced

Effects

vacuum and

UNDERSTANDING

OF TUNGSTEN

CARBIDE-COBALT PREPARATION OF TITANIUM CARBIDE-CHROMIUM ALLOYED-IRON

H.E. Exner.

CERMETS

stadt, Germany.)

HOT

cemented

that TiC-Fe cermets

during

hot

pressing

of

are

chromium,

C and Fe at 1085 to

Cr powder

additions

do not alloy with the

Fe binder

and

should.

and

Cr&

the

Cr

be

1200°C.

added

as

process

requires

a

of toughness

SINTERING

OF SUB-MICRON

CEMENTED

CARBIDES

fracture

expansion

particle were

et

al.

Cr.& to

size.

(Technion,

shows

growth

Haifa,

SOLUTION

OF LOCAL STRESS

effects

vacuum

Mechanical

more

shrinkage

technique. to

sintering are

size but fine WC solid

state stage of sintering. The mechanism

the

were of a

The study was

supported

Predicted

NON-ISOTHERMAL

SINTERING

CARBIDE

FRACTURE

TOUGHNESS

A. Ragulya et al. (Acaademy

of Sciences

of

the Ukraine, Kiev, Ukraine.)

Ni-Mo

binder,

that ultrafine

controlled Tic

Tic

heating

been

sintered

rate

and TIN densified

conditions.

to

Comparison

was

different

heating

modes

structure.

Solid

and liquid

made with

cermets

Pure

between regard

to

state sintering

were :studies and the

sintered

sintering

under

results compared.

Properties

Partial porosity

was

used

to

The

was

investigated.

vary

the

with 25% alloy reached

greater

than was predicted.

study

was

reinforcement

to

STRESS

for

a

cermets

of

with

J. Zackrisson,

H.O.

Andren.

a

University of Technology, Core/rim discussed being

structures

OF

in the light

sufficient

to

cermets

of total

allow

solid

were

C content solution

angles,

of WC-6X0,

curves properties.

and

to

deduce

tracks

and

TiCTiBZ potential in

was wear

et al. (Sandvik

Cormorant

CVD

tools

were

discussed

noted

that

scaling

up

coated

current

reported for

to

by this in

a large

production.

method

service

improvements

was

DC arc

have

industrial

to

it was

laboratory

production

A high

was scale

coated

and

of

to industrial

difficult.

In

diamond

cutting

Tools

AH,

improvements of

have trials

cutting

been and

performance

were reported. TRIBOLOGICAL

of

EVALUATION

HOT FLAME

OF

DEPOSITED

FILMS

S. Hogmark

et al. (Ilniversity

CVD

discussed Effects

stress-strain

of Uppsala.

diamond reported been

and

a

and low friction

diamond

with of

coatings

respect rough

coatings,

to

were

for

diamond

and properties

of

were

applications.

surface,

that a hot flame

used

Structures

mechanical

The results were discussed

AND

MICROSTRUCTURAL

High wear resistance

was described.

The objective was to determine

for wear

wear

Sweden.)

BY INDENTATION

Hardness testing, with differing diamond apex

Sweden.) of

H. Tenerz Sweden.)

DIAMOND AND

S. Chugunova, Y. Milman. (Academy Sciences of Ukraine, Kiev, Ukraine.)

(Chalmers

of

EN24

CHEMICAL VAPOUR DEPOSITED DL4MOND COATED CUTTING TOOLS

smooth

OF CERMETS

wear or

Coatings and ultrahard materials

SMOOTH

OF DUCTILITY CURVES

of

and were

7 MPa.m”‘,

The object

gradient.

STRAIN

HARDMETALS TESTING

make

to

EN3B

characterized

changes. to have

subjected

infiltrated K,,

cermet

of Marl-

applications.

enough

preforms.

EFFECTOFCARBONCONTENTON MICROSTRUCTURE

was

appearance

technique

by infiltration

ceramic

were of near full density. Fracture

toughness

the

Wear

proving

A1303,AI-3!%Mg

characteristics.

DETERMINATION

and testing

that

had been fabricated

partially

and a

I to 2% residual

porosity.

of nano-composites

and

reported

respect

against

experiments

cermets of

size distributions

had

Grenoble,

France.) It was

It was reported

(INP

with

composite

performance

CERMETS

G. Kapelski, A. Varloteaux.

AND WEAR OF

Predicted

OF ALUMINA-

OF

TITANIUM

AND NITRIDE

TiN, with narrow

and

were compared.

for

was discussed.

wear

Mechanical properties, friction wear of a TiCTiBz composite

resistant

any grain size distribution. properties

good

An

stresses

ALUMINIUM-MAGNESIUM NANO-CRYSTALLINE

materials,

part. The method was shown to be valid for

measured

It was reported very

CARBIDE-TITANIUM COMPOSITE

structural considered

properties

by experiment.

wear

of the abrasive

A. Ogwu, T.J. Davies. (I;niversity Chester, Manchester, UK.)

steels.

described.

The local

determine

with

were

to

had been made.

TITANIUM DIBORIDE

debris,

integrated analytical method was used for determination of local stresses instead of a dipole

material

resistance

the

of Technology,

was

and hardness

investigated GRADED

study of graded

WC-Co

shown

in the initial

this, solid state diffusion.

on

was

properties

by fine particle

based

of WC

inhibitors

determine

HIP and

used.

improved

of WC and

stresses. Flaws, at were discussed.

Helsinki, Finland.)

of 0.3 to O.Hpm WC with 6%Co

VC or

coefficients

Co, leading to residual which fracture initiates,

wear

respect

used in testing.

a

and and Cr&

erosive with

PROPERTIES

Techniques

for measurement of toughness were outlined. Note was taken of differences in thermal

composition

abrasive

materials

Link

with and

mechanics.

M. Gasik et al. (University

SIZED

Israel.)

investigated

reviewed

microstructure

A theoretical M. Leiderman

and

was

in a-phase

PROBLEM IN FUNCTIONALLY HARDMETALS

lower temperature giving stoichiometric TiC in a Cr alloyed Fe binder.

Siintering

of Darm-

and free C react in the melt

exothermic

of

investigated

that

t,o

continuum

ferro-

University

carbides

reference

V. Potapenko, MS. Kovahchenko. (Academy of Sciences of Ukraine, Kiev, Ukraine.)

carbide.

(Technical

Development

It was reported

Ni

HARDMETALS

Technical

of Tic- (Ni,Mo)

mechanisms

PRESSING

formed

of

microstructure

THE TOUGHNESS

AND STRENGTH

were described.

BY REACTIVE

of the by the

was made with polycrystalline

on

noted.

some It was

technique

had

deposition. of the coatings

were investigated.

MPR April 1997

45